In particular, we clarify whether the circadian rhythms of PER1, PER2, PER3, CLOCK1, CLOCK2, CLOCK3, CLOCK4, CRY1, CRY2, and BMAL1 are retained in the graft after the transplantation of stem cells derived from T2DM patients. The gene discussed is CRY1; the disease is type 2 diabetes mellitus.